196 research outputs found
Environmental certification in a differentiated duopoly
The articleaims to explore the role of horizontal product differentiation in promoting/hindering firm’s participation in environmental certification. To this purpose, we consider a differentiated
duopoly model where firms compete in both prices and environmental qualities. The result shows that when the level of horizontal differentiation relative to the degree of vertical differentiation
is sufficiently high, only the symmetric equilibrium where both
firms choose to or both choose not to certify their products
exists. Asymmetric equilibrium (vertical dominance equilibrium)
occurs when the level of horizontal differentiation relative to the
degree of vertical differentiation is sufficiently low
Bonding and high-temperature reliability of NiFeMo alloy/n-type PbTe joints for thermoelectric module applications
PbTe is an extremely important thermoelectric (TE) material, due to its high TE conversion efficiency. Consequently, our effort focuses on developing PbTe-based TE modules, which requires developing novel approaches for bonding metallic contacts to PbTe. In this study, Fe, Mo, and NiFeMo alloy foils were directly bonded to n-type PbTe using a rapid hot press at 600, 700, or 800 °C under a pressure of 40 MPa and for various holding times. We find that in the case of Fe and Mo, it is difficult to form a metallurgically bonded high strength joint with PbTe. However, we find that NiFeMo alloy does effectively bond to PbTe at 700 °C, but not at 600 °C. Significant liquid Pb, which might be due to the reaction of PbTe with Ni, is found that penetrates along the NiFeMo grain boundaries near NiFeMo/PbTe joints during bonding at 700 °C where the extent of liquid Pb penetration can be controlled with the time of bonding. Furthermore, the Seebeck coefficient of bulk PbTe with NiFeMo contacts is similar to that without NiFeMo contacts. Finally, the accelerated thermal aging of NiFeMo/PbTe elements at 600 °C for 240 h shows that the failure mechanism of NiFeMo/PbTe joints under operating conditions is the continued formation and penetration of eutectic liquid NiFeMo–PbTe and liquid Pb along the NiFeMo grain boundaries
Improving Question Generation with Multi-level Content Planning
This paper addresses the problem of generating questions from a given context
and an answer, specifically focusing on questions that require multi-hop
reasoning across an extended context. Previous studies have suggested that key
phrase selection is essential for question generation (QG), yet it is still
challenging to connect such disjointed phrases into meaningful questions,
particularly for long context. To mitigate this issue, we propose MultiFactor,
a novel QG framework based on multi-level content planning. Specifically,
MultiFactor includes two components: FA-model, which simultaneously selects key
phrases and generates full answers, and Q-model which takes the generated full
answer as an additional input to generate questions. Here, full answer
generation is introduced to connect the short answer with the selected key
phrases, thus forming an answer-aware summary to facilitate QG. Both FA-model
and Q-model are formalized as simple-yet-effective Phrase-Enhanced
Transformers, our joint model for phrase selection and text generation.
Experimental results show that our method outperforms strong baselines on two
popular QG datasets. Our code is available at
https://github.com/zeaver/MultiFactor.Comment: Camera-ready. Accepted by EMNLP 2023 Finding
Diversify Question Generation with Retrieval-Augmented Style Transfer
Given a textual passage and an answer, humans are able to ask questions with
various expressions, but this ability is still challenging for most question
generation (QG) systems. Existing solutions mainly focus on the internal
knowledge within the given passage or the semantic word space for diverse
content planning. These methods, however, have not considered the potential of
external knowledge for expression diversity. To bridge this gap, we propose
RAST, a framework for Retrieval-Augmented Style Transfer, where the objective
is to utilize the style of diverse templates for question generation. For
training RAST, we develop a novel Reinforcement Learning (RL) based approach
that maximizes a weighted combination of diversity reward and consistency
reward. Here, the consistency reward is computed by a Question-Answering (QA)
model, whereas the diversity reward measures how much the final output mimics
the retrieved template. Experimental results show that our method outperforms
previous diversity-driven baselines on diversity while being comparable in
terms of consistency scores. Our code is available at
https://github.com/gouqi666/RAST.Comment: EMNLP2023 camera-read
Value creation in wine tourism – an exploration through deep neural networks
The aim of this paper is to explore what aspects create experiential value for wine tourists. We synthesize the extant literature into four dimensions for wine tourism value creation, namely, product-related aspects; sensory and affective experiential aspects; cognitive, educational experiential aspects; and social-relational experiential value-creating aspects. So far, most studies merely discuss product-related aspects whilst insights on experiential value are less known. Using online review data from wine tourists in Australia, we develop a novel deep neural network-based framework using an innovative AI-based exploratory design. Results of the case study reveal that in addition to product-related aspects, sensory- and education-related experiential aspects are also highly important for value creation in wine tourism. Theoretical and practical implications, as well as ideas for future research, are discussed.This research is supported by Australian Government
Research Training Program Scholarship; and the collaboration is partially supported by one SRG grant in
the University of Macau
Absolute co-supplement and absolute co-coclosed modules
A module M is called an absolute co-coclosed (absolute co-supplement) module if whenever M ≅ T/X the submodule X of T is a coclosed (supplement) submodule of T. Rings for which all modules are absolute co-coclosed (absolute co-supplement) are precisely determined. We also investigate the rings whose (finitely generated) absolute co-supplement modules are projective. We show that a commutative domain R is a Dedekind domain if and only if every submodule of an absolute co-supplement R-module is absolute co-supplement. We also prove that the class Coclosed of all short exact sequences 0→A→B→C→0 such that A is a coclosed submodule of B is a proper class and every extension of an absolute co-coclosed module by an absolute co-coclosed module is absolute co-coclosed.Scientific and Technical Research Council of Turke
Flow-time minimization for timely data stream processing in UAV-aided mobile edge computing
Unmanned Aerial Vehicle (UAV) has gained increasing attentions by both academic and industrial communities, due to its flexible deployment and efficient line-of-sight communication. Recently, UAVs equipped with base stations have been envisioned as a key technology to provide 5G network services for mobile users. In this paper, we provide timely services on the data streams of mobile users in a UAV-aided Mobile Edge Computing (MEC) network, in which each UAV is equipped with a 5G small-cell base station for communication and data processing. Specifically, we first formulate a flow-time minimization problem by jointly caching services and offloading tasks of mobile users to the UAV-aided MEC with the aim to minimize the flow-time, where the flow-time of a user request is referred to the time duration from the request issuing time point to its completion point, subject to resource and energy capacity on each UAV. We then propose a spatial-temporal learning optimization framework. We also devise an online algorithm with a competitive ratio for the problem based upon the framework, by leveraging the round-robin scheduling and dual fitting techniques. Finally, we evaluate the performance of the proposed algorithms through experimental simulation. The simulation results demonstrated that the proposed algorithms outperform their comparison counterparts, by reducing the flow-time no less than 19% on average
Observation of electronic nematicity driven by three-dimensional charge density wave in kagome lattice KVSb
Kagome superconductors AVSb (A = K, Rb, Cs) provide a fertile
playground for studying various intriguing phenomena such as non-trivial band
topology, superconductivity, giant anomalous Hall effect, and charge density
wave (CDW). Remarkably, the recent discovery of symmetric nematic phase
prior to the superconducting state in AVSb has drawn enormous
attention, as the unusual superconductivity might inherit the symmetry of the
nematic phase. Although many efforts have been devoted to resolve the charge
orders using real-space microscopy and transport measurements, the direct
evidence on the rotation symmetry breaking of the electronic structure in the
CDW state from the reciprocal space is still rare. The underlying mechanism is
still ambiguous. Here, utilizing the micron-scale spatially resolved
angle-resolved photoemission spectroscopy, we observed the fingerprint of band
folding in the CDW phase of KVSb, which yet demonstrates the
unconventional unidirectionality, and is indicative of the rotation symmetry
breaking from to . We then pinpointed that the interlayer coupling
between adjacent planes with -phase offset in the 222 CDW
phase would lead to the preferred twofold symmetric electronic structure.
Time-reversal symmetry is further broken at temperatures below 40 K as
characterized by giant anomalous Hall effect triggered by weak magnetic fields.
These rarely observed unidirectional back-folded bands with time-reversal
symmetry breaking in KVSb may provide important insights into its
peculiar charge order and superconductivity
UHRF1 is required for basal stem cell proliferation in response to airway injury
Cellular senescence is a cell fate characterized by an irreversible cell cycle arrest, but the molecular mechanism underlying this senescence hallmark remains poorly understood. Through an unbiased search for novel senescence regulators in airway basal cells, we discovered that the epigenetic regulator ubiquitin-like with PHD and ring finger domain-containing protein 1 (UHRF1) is critical for regulating cell cycle progression. Upon injury, basal cells in the mouse airway rapidly induce the expression of UHRF1 in order to stimulate stem cell proliferation and tissue repair. Targeted depletion of Uhrf1 specifically in airway basal cells causes a profound defect in cell cycle progression. Consistently, cultured primary human basal cells lacking UHRF1 do not exhibit cell death or differentiation phenotypes but undergo a spontaneous program of senescence. Mechanistically, UHRF1 loss induces G1 cell cycle arrest by abrogating DNA replication factory formation as evidenced by loss of proliferating cell nuclear antigen (PCNA) puncta and an inability to enter the first cell cycle. This proliferation defect is partially mediated by the p15 pathway. Overall, our study provides the first evidence of an indispensable role of UHRF1 in somatic stem cells proliferation during the process of airway regeneration
- …